In most dental, in particular endodontic, procedures the achievement of a good seal between the tooth and the filling composition is essential in order to prevent bacterial recontamination of the root canal and ensure long-term clinical success (1, 2). The presence of marginal gaps between the interfaces of retrofilling compositions and root dentin are sites of possible microleakage (3, 4) and penetration of microorganisms and their toxins (5, 6).
Mineral trioxide aggregate (MTA) (ProRoot Dentsply-Maillefer, Baillagues, Switzerland) has been recently introduced for root perforations sealing and as a retrograde filling composition (7,8).
The principal compounds present in MTA are tricalcium silicate, tricalcium aluminate, tricalcium oxide and silicate oxide (7).
Some difficulties are reported by clinicians when using MTA including poor handling characteristic and lengthy setting time. It would be useful to improve those characteristics (9, 10, and 11). Furthermore, a recent study conducted by using a fluid conductive device and by capillary flow porometry reported that root-end fillings performed using MTA presented microleakage (12).
The fluid filtration method was found to be a valid technique to evaluate the sealing ability of root-end filling compositions (13, 14).